1. Field of the Invention
The present invention relates to an electronic device including plate shaped shields, which are provided on a front side and a back side of a circuit board, for improving electromagnetic tolerance of the electronic device.
2. Description of the Related Art
There is known a conventional electronic device (for example, personal computer, game device, or audio-visual device), which includes a plate shaped shield covering a circuit board in order to ensure electromagnetic tolerance of the electronic device (that is, in order to block an electromagnetic wave emitted from an electronic component on the circuit board, and in order to reduce an influence from an electromagnetic wave which other electronic device emits).
In U.S. Pat. No. 6,930,891, a shield has a plurality of plate-spring-like connecting portions formed on the edge of the shield. Through the connecting portions, the shield is in contact with the conductive pattern for grounding formed on the front surface of the circuit board. By using plate-spring-like connecting portions, connection stability between the conductive pattern and the shield is improved.
Specifically, the shield of U.S. Pat. No. 6,930,891 has a plate shaped portion (hereinafter, referred to as upper plate portion) which is spaced apart from the front surface of the circuit board and is parallel to the circuit board. Further, a plurality of slits are formed in the edge of the upper plate portion. Portions between the slits function as the connecting portions. Each of the connecting portions is bent downward at midpoint thereof to extend toward the front surface of the circuit board, and is in contact with the conductive pattern at the lower end of the connecting portion.